Soft, flexible composition and method for making same

ABSTRACT

There is provided a composition comprising a unique polymeric compound that provides a soft, flexible product. There is also provided a unique polymeric tampon applicator that is soft and flexible. When used as a tampon applicator barrel, the barrel is more comfortable and has improved ease of insertion. The polymeric compound primarily comprises a thermoplastic resin and a block copolymer that exhibit unique load, energy and modulus of elasticity properties. The polymeric compound should also include a plasticizer and a compatibilizer/flow modifier, and may include a slip/mold release agent, an antioxidant, and even a pigment. There is also provided a method for making the polymeric compound that will be formed into a product, such as an applicator or applicator barrel in which all of the above ingredients, except for the thermoplastic resin, are combined and formed into soft pellets. The soft resin pellets are then dry blended with pellets of the thermoplastic resin. The mixture of the thermoplastic resin pellets and the soft resin pellets are then melted and injection molded into the desired shape. There is thus provided a method of making a soft, polymeric tampon applicator or tampon applicator barrel.

RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.09/648,883 filed on Aug. 25, 2000, pending, which is a divisional ofapplication Ser. No. 09/075,097 filed May 8, 1998 and issued into U.S.Pat. No. 6,254,565, which is a continuation of application Ser. No.08/547,766 filed Oct. 24, 1995 and issued as U.S. Pat. No. 5,986,000,which is a continuation-in-part of application Ser. No. 08/447,289 filedMay 22, 1995 and issued as U.S. Pat. No. 5,681,894; of which, each ofthe above-cited applications are incorporated in their entirety byreference herein.

BACKGROUND OF THE INVENTION

I. Field of the Invention

The present invention relates generally to a soft, flexible material.More particularly, it relates to a thermoplastic composition that can beused to make a variety of products that are soft and flexible. Thethermoplastic composition is, preferably, a combination of a polyolefinand thermoplastic elastomeric materials. In addition, the thermoplasticcomposition may include one or more additional thermoplastic materials.Some uses envisioned for this composition are, for example, catamenialdevices, baby care products, such as baby bottles and holders,pacifiers, toothbrushes and containers. One particular use of thecomposition is for a tampon applicator and especially a tamponapplicator barrel, that will be more comfortable and has a greater easeof insertion into the vagina greater ease of insertion into the vaginathan known such applicator barrels.

II. Description of the Prior Art

Polyethylene is a thermoplastic that is the standard resin used toproduce a number of products, including plastic tampon applicators. Asofter applicator, especially an applicator barrel that is morecomfortable is a desirable feature of a tampon applicator in order toprovide improved ease of insertion.

It is generally known that thermoplastic elastomer articles may becombined with polyethylene to improve the strength and toughness of sucharticles. For example, U.S. Pat. No. 4,593,063 to M. A. Jones, et al.,which issued Jun. 3, 1986, provides a reinforced rigid polymer blend,which yields a high gloss finish when injection molded. Thethermoplastic elastomer includes 25 to 35 percent of a butadienethermoplastic elastomer having a molecular weight of about 70,000 toabout 100,000, a styrene content from about 25 to about 44 percent byweight and a melt flow rate from about 8 to about 15 grams per 10minutes. The butadiene thermoplastic elastomer is blended with fromabout 54 to about 75 percent of a rigid polymer, such as polyethylene.

Polymers have also been combined with polyethylene to improve theirreaction to each other when heated or otherwise processed. For example,U.S. Pat. No. 4,678,834 to D. W. Boivin, et al., which issued Jul. 7,1987, provides a polyolefin blend comprising a major portion ofpolyethylene and aminor portion of a second polymer, such as astyrene-butadiene-styrene copolymer. The second polymer contains areactive agent that is capable of reacting with polyolefins in a moltenstate. The reactive agent modifies or stabilizes the polymer duringprocessing or during use.

Polymers may also be added to polyethylene to permit a breakdown of itsstructural composition. Polyethylene, which is normally stable, has alsobeen combined with less stable materials to produce biodegradableproducts. Such biodegradable products include ingredients that causeoxidative actions in order to break down the polyethylene. For example,U.S. Pat. No. 5,212,219 to G. J. L. Griffin, which issued May 18, 1993,provides a degradable article prepared from a blend of polyethylene anda less stable polymer or copolymer, such as a styrene-butadiene blockcopolymer. The composition further comprises an antioxidant active overa limited period and a pro-oxidant that causes a sharp loss of physicalstrength on depletion of the anti-oxidant. In addition, the presence offiller particles of a biologically sensitive material accelerates thebiological breakdown of the polymer/copolymer blend.

Improvements to the pelletizability and drapability of a polymercomposition, without causing the composition to biodegrade, are alsoknown. For example, U.S. Pat. No. 4,833,195 to A. M. Adur, et al., whichissued May 23, 1989, provides a thermoplastic polymer composition thatcan be conveniently converted into a drapable film or fabric. Thecomposition has a low Shore A hardness, i.e., below about 95, and a highmelt flow rate about 30 grams/10 minutes to 1100 grams/10 minutes at 230degrees Celsius and 2.16 kilograms. Drapability is an important propertyof products that drape against a user's skin, such as baby diapers orsanitary napkins.

However, none of the above patents describe or suggest a tamponapplicator that is composed of such materials. In fact, none of theabove patents suggest the inventive combination of polyethylene and theunique elastomeric composition which improves flexibility, strength andtear resistance and, perhaps, softness, and can function as acompatibilizer with other thermoplastic polymeric materials. Thus, theabove patents do not suggest a flexible, soft tampon applicator having aunique blend of polyethylene and a rubber type composition that includesa thermoplastic elastomer (TPE), namely a styrene-butadiene-styreneblock copolymer, which applicator provides for comfortable and easyinsertion into the vagina.

Further, thermoplastic resins are much less expensive than elastomericmaterials. To minimize the costs of tampon applicators, one desires thegreatest amount of thermoplastic resin as possible in the composition,but without adverse affects. Accordingly, to achieve the benefits of aflexible and easy to insert tampon applicator barrel and yet minimizecosts, it is desired to use as little as possible of the elastomercomponents and as much as possible of the thermoplastic resin componentin the tampon applicator barrel.

Other projected products, such as, for example, a holder for nurserliners or a nurser bottle, may desire the flexibility of the material inorder to assist a child or parent in gripping the product and, perhaps,squeeze the product to remove contents.

SUMMARY OF THE INVENTION

Against the foregoing background, it is a primary object of the presentinvention to provide a composition that comprises a polyolefin and athermoplastic elastomer.

It is another object of the present invention to provide such acomposition that favorably adjusts the modulus of elasticity of thecomposition.

It is yet another object of the present invention to provide such acomposition in a thermoplastic-type tampon applicator so that thebarrel, in particular, is soft and flexible to provide more comfort andimproved ease of insertion.

It is a further object of the present invention to provide such a tamponapplicator having at least one styrene-butadiene-styrene block copolymerto achieve such desired properties.

To accomplish the foregoing objects and advantages, the presentinvention, in brief summary, is a soft, flexible composition thatcomprises a thermoplastic resin and at least twostyrene-butadiene-styrene block copolymers, each having a differentpercent by weight of styrene in an amount sufficient to reduce themodulus of elasticity.

A preferred use of the composition is as a tampon applicator barrel thatis more comfortable and has improved ease of insertion into the vagina.The tampon applicator barrel comprises a thermoplastic resin and atleast one thermoplastic elastomer in an amount sufficient to adjustfavorably the modulus of elasticity of the tampon applicator barrel.

More specifically, the present invention is a soft, flexible tamponapplicator that provides more comfort and improved ease of insertioninto the vagina by the combination of a low density polyethylene and atleast one styrene-butadiene-styrene block copolymer. In one preferredembodiment, there are at least two styrene-butadiene-styrene blockcopolymers, each having a different percent by weight of styrene.

In a most preferred embodiment, there are threestyrene-butadiene-styrene block copolymers each having a percentage byweight of styrene that is different than that of the other twocopolymers. In particular, the first styrene-butadiene-styrene blockcopolymer has about 29 percent by weight of styrene, the secondstyrene-butadiene-styrene block copolymer has about 31 percent by weightof styrene, and the third styrene-butadiene-styrene block copolymer hasabout 43 percent by weight of styrene.

The polymeric resin should further comprise one or more of thefollowing: a plasticizer and a compatibilizer/flow modifier, and mayfurther comprise other ingredients, such as a pigment, a slip/moldrelease agent, an antioxidant and, perhaps, an antistat ingredient.

The present invention is also a method for making a composition that canbe made into a soft, flexible product. An elastomer composition ismelted and combined to form a melted resin, which is then extruded intoa plurality of soft resin pellets. The plurality of soft resin pelletsare then dry blended with a plurality of pellets of a polyolefin, forexample, low density polyethylene to form a pellet mixture. Finally, thepellet mixture is melted together to form a polymeric compound that maybe molded to a desired shape. In a preferred embodiment, the method isused to make a tampon applicator, especially an applicator barrel thathas a soft and flexible structure for more comfort and improved ease ofinsertion into the vagina.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a new polymeric compound or compositionthat is a combination of a polyolefin and a rubber type composition thatadjusts the softness and flexibility of the polymeric compound. Asstated above, while it is envisioned that this material may be used toform a variety of products, such as, for example, baby or nurser bottlesand holders, pacifiers, toothbrushes and containers, a preferredapplication is for catamenial devices. A particularly preferredapplication is a tampon applicator, especially an applicator barrel,composed of this new polymeric compound.

To minimize costs, it is preferable that the tampon applicator have anapplicator barrel that uses the polymeric compound of the presentinvention, while the plunger is made, perhaps, of less expensivematerial. A softer applicator barrel is more comfortable and is adesirable feature of a tampon applicator in order to provide improvedease of insertion. Accordingly, the present application is directed to atampon applicator barrel, however it can be used for the entire tamponapplicator.

The polymeric compound comprises polyolefin and a rubber typecomposition that adjusts the softness and flexibility of the polymericcompound and, thus, the tampon applicator. For the preferred embodiment,the polyolefin is a low density polyethylene and the rubber typecomposition includes a thermoplastic elastomer. The thermoplasticelastomers could include thermoplastic vulcanizates, thermoplasticolefins, styrene block copolymers, thermoplastic urethanes andcombinations thereof. In the most preferred embodiment, thethermoplastic elastomer is a plurality of styrene-butadiene-styreneblock copolymers.

The primary supporting structure of the soft applicator barrel isprovided by the polyolefin. The preferred type of polyolefin ispolyethylene, and, more preferably, low density polyethylene. Thepolyethylene can be a linear low density polyethylene. For the preferredembodiment, the polyolefin is about 25 to about 75 percent by weight ofthe total weight of the polymeric compound.

The thermoplastic elastomers are combined with the polyolefin in amountssufficient to adjust the elasticity of the polymeric compound.

Styrene-butadiene-styrene block copolymers are the preferredthermoplastic elastomers. A combination of three different types ofstyrene-butadiene-styrene block copolymers having different contents ofstyrene is the more preferred. In a most preferred embodiment, a firststyrene-butadiene-styrene block copolymer has 29 percent by weight ofstyrene in the block copolymer, a molecular weight of 80,000 and a meltflow rate 8 grams per 10 minutes, a second styrene-butadiene-styreneblock copolymer has 31 percent by weight of styrene, a molecular weightof 100,000 and a melt flow rate less than 1 gram per 10 minutes, and athird styrene-butadiene-styrene block copolymer has 43 percent by weightof styrene, a molecular weight of 58,000 and a melt flow rate 23 gramsper 10 minutes. The melt flow rate for all threestyrene-butadiene-styrene block copolymers is measured at 200 degreesCelsius with a 5.0 kg load. Such first, second and thirdstyrene-butadiene-styrene block copolymers are commercially available asVector Resin 8550, Vector Resin 2518, and Vector Resin 6241,respectively. These copolymers are manufactured by Dexco Polymers (aDow/Exxon Partnership) of Houston, Tex.

Each of the first, second and third styrene-butadiene-styrene blockcopolymers is about 5.5 to about 16.6 percent by weight of the totalweight of the polymeric compound. Accordingly, the weight of the blockcopolymers is about 16.5 to about 49.80 percent by weight of the totalweight of the polymeric compound.

The combination of these three block copolymers has been found toprovide the optimum viscosity desired so that the thermoplastic resinphase, namely polyethylene, and the rubber phase are compatible.

The rubber type composition that is added to the polyolefin may alsoinclude other materials. It is preferred that a plasticizer, such asmineral oil, be used to reduce the viscosity and hardness. Theplasticizer is about 5 to about 15 percent by weight of the total weightof the polymeric compound. In addition, the rubber type composition maycontain a filler, such as CaCO3 or talc.

It is also preferred that the polymeric compound include acompatibilizer/flow modifier, which assists in the blending orcompatibilization of the thermoplastic resin and the rubber materials,and to improve the tear resistance and elongation properties of thecompound. Preferably, the compatibilizer/flow modifier is a copolymer.In the preferred embodiments, the copolymer is an alpha olefincopolymer, namely an ethylene copolymer. In the most preferredembodiment, the ethylene copolymer is ethylene methyl acrylate.Alternative alpha olefin copolymers that can be used are ethylene vinylacetate, ethylene ethyl acrylate, ethylene butyl acrylate and mixturesthereof. Ethylene methyl acrylate is the most preferred since it, unlikeethylene vinyl acetate, will not decompose under high moldingtemperatures, and is less expensive than either ethylene ethyl acrylateor ethylene butyl acrylate.

The compatibilizer/flow modifier is present in an amount about 2.9 toabout 8.6 percent by weight of the total weight of the polymericcompound.

The rubber type composition may further include additives, such as apigment or color additive, a slip/mold release agent, an antioxidantand/or an antistat, that may be necessary to facilitate the manufactureor otherwise improve the quality of the tampon applicator or barrel.

The pigment, that is chosen to provide the desired aesthetic effect, ispreferably titanium dioxide. It is about 0.5 to about 1.5 percent weightof the total weight of the polymeric resin.

The slip/mold release agent is, preferably, a fatty acid amide, such as,erucamide. Alternatively, the slip/mold release agent can be metallicstearates, calcium stearate, ethylene bis stearamide and ethylene bisoleamide. In a preferred embodiment for use in a tampon applicatorbarrel, erucamide is present in an amount about 0.8 percent by-weight ofthe total weight of the polymeric compound. While erucamide is apreferred slip release agent, an erucamide slip agent may undergosubstantial blooming subsequent to molding. Such blooming will result inan agglomeration of the erucamide slip release agent on the surface ofthe molded polymeric article that can cause gumming and contaminationproblems in equipment if substantial post-molding handling of thearticle is required. Surprisingly, stearyl erucamide has been found toavoid the blooming problem. The use of higher amounts, about 3%, ofstearyl erucamide is preferred. Accordingly, stearyl erucamide has beenfound to particularly improve the process of manufacture of a tamponapplicator and tampon applicator barrel that require significanthandling after molding. When stearyl erucamide is used, a higher amountof the release agent, for example up to about 3 percent by weight of thetotal weight of the composition, may be used. Accordingly, the slip/moldrelease agent can be present in a range about 0.4 to about 3 percent byweight of the total weight of the polymeric compound.

The antioxidant provides stability to the polymeric compound. It ispreferred that the antioxidant be a combination of two antioxidants. Oneantioxidant is tetrakis [methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane. The otherantioxidant is tris (2,4-di-tert-butyl phenyl) phosphite. Suchantioxidants/stabilizers are manufactured under the product namesIrganox 1010 and Irgafos 168, respectively, by Ciba-Geigy Corporation.Each antioxidant is about 0.05 to about 0.15 percent by weight of thetotal weight of the polymeric compound.

When there is substantial handling of the molded article, such as, forexample, a tampon applicator or tampon applicator barrel, the mostpreferred embodiment of the present composition has the followingingredients and their approximate percent by weight of the totalcomposition: TABLE A about 63% low density polyethylene; about 8% firststyrene-butadiene-styrene block copolymer having about 29 percent ofstyrene; about 8% second styrene-butadiene-styrene block copolymerhaving about 31 percent of styrene; about 8% thirdstyrene-butadiene-styrene block copolymer having about 43 percent ofstyrene; about 7% mineral oil as the plasticizer; about 4% ethylenemethyl acrylate as the compatibilizer/flow modifier; about 1% titaniumdioxide as the pigment; about 1.5% stearyl erucamide as the slip/moldrelease agent; less than 1% tetrakis [methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane as a stabilizer/antioxidant; and lessthan 1% tris(2,4-di-tert-butyl phenyl) phosphite as astabilizer/antioxidant.

Higher styrene contents would tend to make the elastomer material lesssoft and less flexible. In a preferred embodiment of the polymericcompound, the amount of the third styrene-butadiene-styrene blockcopolymer is about one-half of one percent less than the amount of thefirst or second styrene-butadiene-styrene block copolymers.

It is to be understood that an antistatic agent or antistat may be addedto the polymeric compound but is not a part of the preferred embodiment.The antistat imparts a slight to moderate degree of electricalconductivity to plastic compounds, thus preventing the accumulation ofelectrostatic charges on the soft applicator. The antistat may beincorporated in the ingredients before molding, or applied to the outersurface of the tampon applicator or barrel after molding.

The preferred method for making the preferred polymeric compound that isformed into an applicator or applicator barrel is as follows. The threestyrene-butadiene-styrene block copolymers, mineral oil, ethylene methylacrylate, stearyl erucamide and the antioxidants (and pigment, if used)are weighed and then combined in a twin screw extruder that melts andblends the ingredients and forms a melted resin. The melted resin isthen extruded and cut into soft resin pellets. These soft resin pelletsare then dry blended with pellets of the remaining ingredient, i.e. thelow density polyethylene, to form a pellet mixture. The pellet mixtureof low density polyethylene pellets and soft resin pellets are thenmelted and injection molded to form the desired shape for the softtampon applicator or applicator barrel.

An alternative method for making the preferred polymeric compound thatis formed into an applicator or applicator barrel includes weighing allingredients including the low density polyethylene and then combiningthem in a twin screw extruder to form the melted compound. The meltedcompound is then extruded and cut into pellets which are then injectionmolded to form the desired shape for the tampon applicator or applicatorbarrel.

In order to exemplify the effectiveness of the composition comprisinglow density polyethylene and the styrene-butadiene-styrene blockcopolymers verses conventional low density polyethylene basedcompositions, the following comparison test was conducted of tamponapplicator barrels.

An element of “softness” is flexibility. In order to test forflexibility, Instron compression testing was performed to comparedifferences in flexibility of the tampon applicator barrel of thepreferred embodiment against the four known thermoplastic applicatorbarrels.

The Instron compression test was designed to treat the whole barrel as atubular specimen. A {fraction (5/8)} inch wide platen is used toradially compress the applicator barrel against a 6 inch anvil. Thespecimen is placed on the anvil so that the platen engages the barrel atan axial location between {fraction (13/8)} inch and {fraction (23/16)}inch as measured from the finger grip end of the applicator barrel. Thespecimen is compressed by a total of 0.25 inch at a rate of 0.5inch/minute.

As shown in Table B below, the Instron compression test produced thefollowing results. TABLE B Instron Compression Testing LOAD YOUNG'SMODULUS ENERGY lbs. PSI lbs.-inch (std. dev.) (std. dev.) (std. dev.)Tampon applicator barrels having an outside diameter about 0.67 inches+/− .07 inches and a wall thickness about .027 inches +/− .003 inchesKnown Branded 2.22 to 3.59 191.9 to 277.5 0.28 to 0.46 Thermoplastic(0.16) (0.22) (20.4) (28.9) (0.02) (0.03) applicators Preferred 1.74104.2 0.22 Composition (0.10) (11.8) (0.01) Applicator Tampon applicatorbarrels having an outside diameter about 0.56 inches +/− .06 inches anda wall thickness about .027 inches +/− .003 inches Known Branded 3.11 to4.85 239.4 to 474.8 0.40 to 0.62 Thermoplastic (0.28) (0.27) (26.6)(59.3) (0.04) (0.05) applicators Preferred 1.96 113.0 0.25 Composition(0.20) (17.6) (0.03) Applicator

The standard deviation of the four known branded thermoplasticapplicator barrels is different for each applicator barrel. Accordingly,there is a range for the known thermoplastic applicators with a standarddeviation for the lowest number and largest number in the range. Itshould be understood that the grade of material, diameter and wallthickness of the barrel are the three factors that affect flexibility,and that flexibility is determined by the load, Young's modulus ormodulus of elasticity, and energy.

Young's modulus, also known in the art as modulus of elasticity, is ameasurement for flexibility. It is the ratio of a nominal stress tocorresponding strain below the proportional limit of a material. Young'smodulus is expressed in force per unit area, usually lbs. per squareinch (PSI) as shown in Table B.

The larger diameter, preferred composition applicator has an outsidediameter about 0.60 inches. As shown in Table B, it has been foundsignificantly more flexible than known thermoplastic applicators. Forthe larger outside diameter applicator barrels, about 0.60 to about 0.74inches (0.67 inches+/−0.07 inches), the load results indicate that theapplicator barrel made with the preferred polymeric compound requiresabout 1.74 lbs. to radially compress the applicator barrel by 0.25inches, whereas the four known thermoplastic applicator barrels requireabout 2.22 lbs. to about 3.59 lbs. In addition, Young's modulus or themodulus of elasticity for the present applicator barrel is about 104psi, whereas the known thermoplastic applicators is about 192 psi toabout 278 psi. Also, the energy to compress by 0.25 inches the presentapplicator barrel is about 0.22 lbs.-inch, whereas the known applicatorbarrels are about 0.28 to 0.46 lbs.-inch. Preferably, with barrels ofthis dimension, the thermoplastic elastomer will be used in an amountsufficient to adjust the energy needed to compress the tampon applicatorbarrel by 0.25 inches to less than 0.26 lbs.-inch and adjust thesupportable load of the tampon applicator to less than about 2.06 lbs.

It would be expected that the smaller the outside diameter of thebarrel, the higher the Young's modulus. Accordingly, the results of thepresent applicator barrel (having an outside diameter of about 0.60inches) to the known applicator barrels having an outside diameter from0.60 to 0.74 is even more remarkable.

For the smaller outside diameter applicator barrels, i.e. about 0.50 toabout 0.62 inches (0.56 inches+/−0.06), the load results indicate thatthe applicator barrel made with the preferred polymeric compound (havingan outside diameter about 0.54 inches) requires about 1.96 lbs. toradially compress the applicator barrel 0.25 inches, whereas the knownthermoplastic applicator barrels require about 3.11 lbs. to about 4.85lbs. to compress 0.25 inches. In addition, the modulus of elasticity forthe present applicator barrel is about 113 psi, whereas the modulus ofelasticity for the known thermoplastic applicator barrels is about 240psi to about 475 psi. Also, the energy to compress by 0.25 inches thepresent applicator barrel is about 0.25 lbs.-inch, whereas such energyto compress the known applicator barrels the same amount is about 0.40to 0.62 lbs.-inch. Preferably, with barrels of this dimension, themodulus of elasticity will be less than 79 psi, and the thermoplasticelastomer will be used in an amount sufficient to adjust the energyneeded to compress the tampon applicator barrel by 0.25 inches to lessthan 0.36 lbs.-inch and adjust the supportable load of the tamponapplicator to less than about 2.83 lbs.

Thus, present or soft applicators made with the preferred polymericcompound of the present invention have a load, modulus of elasticity andenergy approximately one-half that of all known thermoplastic applicatorbarrels. In addition, applicator barrels of the present invention havebeen found by consumers as a unique, softer applicator barrel due to thetactile feel of the applicator barrels.

In addition to improved “softness” and “flexibility”, the polymericcompound or composition of the present composition has been found tohave improved strength and tear resistance. The following testdemonstrates the unexpected improvement in strength and tear resistance.

Samples A through D were manufactured by combining three blockcopolymers, a plasticizer, a compatibilizer/flow modifier, mold releaseagents, antioxidants/stabilizers and a pigment, and in the percentagesset forth in Table C. They were compared with a “comparative” samplemade of a combination of one block copolymer, along with an analogousplasticizer, mold release agents, antioxidants/stabilizers and pigment.For each sample and the comparative, the mixed compositions were madeaccording to the preferred method set forth above. In particular, eachmixed composition was passed through a twin screw extruder that meltedand blended the ingredients and extruded to form a melted resin that isthen cut into soft resin pellets. The soft resin pellets were then dryblended with pellets of low density polyethylene to form a pelletmixture. The pellet mixture was then melted and injection molded to formASTM test articles. The four samples and the comparator were evaluatedfor elongation, tensile strength, and tear resistance (see Table D). Asevidenced by the results of Table D, the four samples, each with threeblock copolymers, as compared to the one block copolymer comparative,demonstrated significantly improved strength and tear resistanceproperties.

In addition, the preferred composition noted as D in Table D and alsoset forth in Table A, has the best combination of softness, flexibility,strength and tear resistance of all compositions tested. TABLE CIngredients A B C D Comparative Styrene-butadiene-styrene 10.48 8.9011.93 8.0 29.97 (29% styrene) Styrene-butadiene-styrene 10.48 8.90 11.938.0 — (31% styrene) Styrene-butadiene-styrene 7.20 8.32 8.22 8.0 — (43%styrene) Mineral Oil 7.13 8.12 8.12 7.0 10.23 Ethylene-methyl acrylate —4.68 — 4.0 — (20MI) Stearyl erucamide — 1.83 — 1.5 0.63 Irganox 1010<0.1 <0.1 <0.1 <0.1 <0.1 Irgafos 168 — <0.1 <0.1 <0.1 <0.1 Low densitypolyethylene 58.40 58.40 58.20 63.0 58.20 Ethylene vinyl acetate 4.80 —— — — Titanium 0.80 0.78 0.80 1.0 0.80 Erucamide 0.64 — 0.63 — 0.63

TABLE D Sample A B C D Comparative Elongation, % (ASTM D638) 170 246 162227 86 Tensile Strength psi 820 878 862 917 753 (ASTM D638) TearResistance 218 234 167 248 132 (ASTM D624)

The present invention having been thus described with particularreference to the preferred forms thereof, it will be obvious thatvarious changes and modifications may be made therein without departingfrom the spirit and scope of the invention as defined in the appendedclaims.

1. A method for making a tampon applicator barrel having a soft,flexible supporting structure comprising the steps of: providing anelastomeric composition with at least two styrene-butadiene-styreneblock copolymers; melting said elastomeric composition thereby forming amelted resin; extruding said melted resin into a plurality of softpellets; dry blending said plurality of soft pellets with a plurality ofpellets comprising low density polyethylene to form a pellet mixture;melting said pellet mixture to form a polymeric compound; and moldingsaid polymeric compound to a desired shape to form the tampon applicatorbarrel.
 2. The method of claim 1, wherein said at least twostyrene-butadiene-styrene block copolymers is at least threestyrene-butadiene-styrene block copolymers.
 3. The method of claim 1,wherein said at least two styrene-butadiene-styrene block copolymerseach have a different percentage by weight of styrene present in amountssufficient to adjust an elasticity of said composition.
 4. The method ofclaim 2, wherein said at least three styrene-butadiene-styrene blockcopolymers each have a different percentage by weight of styrene presentin amounts sufficient to adjust an elasticity of said composition. 5.The method of claim 1, wherein said elastomeric composition furthercomprises one or more compounds selected from the group consisting ofplasticizer, compatibilizer/flow modifier, slip/mold release agent,antioxidant, and any combinations thereof.
 6. The method of claim 2,wherein at least one of said at least three styrene-butadiene-styreneblock copolymers has about 29 wt. % styrene.
 7. The method of claim 2,wherein at least one of said at least three styrene-butadiene-styreneblock copolymers has about 31 wt. % styrene.
 8. The method of claim 2,wherein at least one of said at least three styrene-butadiene-styreneblock copolymers has about 43 wt. % styrene.
 9. The method of claim 2,wherein said at least three styrene-butadiene-styrene block copolymershas a first styrene-butadiene-styrene block copolymer with about 29 wt.% styrene, a second styrene-butadiene-styrene block copolymer with about31 wt. % styrene, and a third styrene-butadiene-styrene block copolymerwith about 43 wt. % styrene.
 10. The method of claim 1, wherein said atleast two styrene-butadiene-styrene block copolymers are present in anamount about 16.5 wt. % to about 49.8 wt. %, based on the total weightof the composition.
 11. The method of claim 1, wherein said low densitypolyethylene is present in an amount about 25 wt. % to about 75 wt. %,based on the total weight of the composition.
 12. The method of claim 5,wherein said compatibilizer/flow modifier is an ethylene copolymer. 13.The method of claim 5, wherein said compatibilizer/flow modifier isethylene methyl acrylate.
 14. The method of claim 5, wherein saidcompatibilizer/flow modifier is present in an amount about 2.9 wt. % toabout 8.6 wt. %, based on the total weight of the composition.
 15. Themethod of claim 5, wherein said plasticizer is mineral oil.
 16. Themethod of claim 5, wherein said plasticizer is present in an amountabout 5 wt. % to about 15 wt. %, based on the total weight of thecomposition.
 17. The method of claim 5, wherein said slip/mold releaseagent is stearyl erucamide.
 18. The method of claim 5, wherein saidantioxidant is selected from the group consisting of tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane,tris(2,4-di-tert-butyl phenyl) phosphite, and any combinations thereof.19. The method of claim 5, wherein said antioxidant is present in anamount about 0.05 wt. % to about 0.15 wt. %, based on the total weightof the composition.